Arrangement for producing oscillations by means of vacuum tubes



Nov.- 16 1926. v 1,606,809

B. ROSENBAUM ARRANGEMENT FOR PRODUCING OSCILLATIONS BY MEANS 0E VACUUI TUBES Filed Oct. 31 1921 '2 Sheets-Sheet 1 W m VE/V 701? @M,9M -MM- &M ATTORNEYS Ndv. 16 192s. 1,606,809

5 ROSIENBAUM ARRANGEMENT FOR PRQDUCING OSCILLAT IONS BY MEANS OF VACUUM TUBES Filed; Oct. 31 1921 2 s eets-shew, 2

WITNE s2 iINVENTQR g z L/ V Bra/m Raye/Maw;

v v BY- ATTORNEY Patented Nov. 16,1926.

A UNITED STATES BRUNO ROSENBAUM, OI BERLIN, GERMANY, ASSIGNOR '10 WESTHVGHOUSE EIiECTRIC v PATEINT OFFICE.

& MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ARRANGEMENT For. rEoDUoINc' OSCILL'ATIONS :BY MEANS or VACUUM rUBEs.

- Application filed October 31, .1921, Serial No. 511,773, and in Germany January 22, 1921 This invention relates to oscillation generators of the. vacuum-tube type.

It is an object of this invention to provide a means by which a source of direct cur-v rent may be made to sustain a continuous hi h-frequency oscillation.

i i lore specifically stated, the object of this invention is'to provide a vacuum-tube path for the current in shunt with the main w vacuum-tube path and to vary the distribution of the current between the two paths at the period of the oscillations.

Other objects of the invention and specific details of the construction will become evident from the following specification and the accompanying drawing, in which- Figure 1 is a diagram of a form of the device using one vacuum tube.

' Fig. 2 is a diagram of a modification in which two Vacuum tubes are used.

.Fig. 3 is a diagram of a further modification in which the changes in the electron path are controlled by a magnet, and

Fig. at shows a further modification in which the. are is intermittent.

The tube shown in Fig. 1 may be a gasfree vacuum tube or a mercury-arc tube. V The cathode 2 is illustrated as heated by the battery 3 through the adjustable resistance 4, but any other form of hot cathode, such as the surface of a pool of mercury, may be .used. The tube is supplied with two anodes providing two divergent space-current paths. The external circuit connected to the anode 6 includes a condenser 7 having an inductor 19 shunted about it. The resonant circuit, comprising the condenser and I inductor, isconnected to one pole of a directcurrent source 8. The other pole of this source is connected to the cathode 2. Be-

tween the two poles of the source 8, is a condenser 9 which affords passage for the high-frequency current; The positive pole of the source 8 is also connected to-the anode 5 and thenegative pole is connected to the grid or supplemental electrode 10. This connection to the. grid includes a coil 11 inductivelyrelated to the coil'19 inthe oscil- 'lating circuit. In the operation of this device, the space current between the cathode 2 and the .anode 6 charges the condenser 7 and, when this condenser reaches its maximum potential, the" counter-electromotive force of it checks the space current to the anode 6. The relation of the direction ,of the Windings of the coils 11 and 19 is such that, at the time the counter-electromotive force of the condenser is checking the space current, the potential impressed upon the grid 10 by the electromotive forceinduced in the coil 11 is of a sign that assists the flow of space current between the cathode 2 and the anode.

5. The .diminution of the space current to the anode 6 is, therefore, accompanied by an increase in the space current to the anode 5. As the electron emission from the cathode 2 is virtually constant, increase of the current in one path is necessarily accompanied b a decrease of current in the other path. f the tube 1 contains gas, such asv mercury vapor, the limit of the total current is fixed by the ionization, so that it is still true that increase in the current to the anode 5 is accompanied by a decrease of current to the anode 6. It is, therefore, apparent that/the changes, due to the variations of the charge upon the condenser 7, set up oscillations. The period of these oscillations is fixed by the constants of the circuit comprising the condenser 7 and the indicator 19. Thus, the energy derived from the source 8 gives rise to sustained oscillations in the oscillating circuit. The inductor 19 may be used to supply energy to an antenna. or to any other working circuit; also the connection tothe anode 5 may contain any Working -,or absorbing circuit that is desired.

In the form illustrated in Fig. 2, the source 8 is supplied with an adjustable resistance 17 and there are two choke coils direct-current 12 and 14 between the source and the con- I denser 9. The connection from the'positive side of the source goes to two anodes, but,

.in this form, theseanodes are in separate tubes 15 and 16. Each of these tubes is provided with a. cathode heated by its own attery, and the two'cathodes are connected tothe negative side of the source. The connection to the anode of the tube 1.6 in

cludes a condenser 7 and an inductor 19, as

in the formillustrated in Fig. 1. The coil :11, in inductive relation to the 0011 19,

applies a varying potential to the of the tube 15. The grid of the tube 16 is provided with any grid biasing device. Preferably, this device is made adjustable.

The operation of this form of the device is closely similar to that described in connection with Fig. 1. Oscillations are set up in the circuit including the condenser 7 and the inductor 19. These cause fluctuations upon the grid of the tube 15, through the coupling between coils 11 and 19. The relation of the windings of these two coils is such that, when the current through the tube 16 is diminishing, the charge upon the grid in the tube 15' is of a sign to cause the current through the tube 15 to increase.

The constant character of the source 8, together with the steadying effect of the choke coils 12 and 14: and the condenser 9, causes the increase in the current through the tube 15 to be accompanied by a further decrease in the current through the tube 16. Consequently, once oscillations are started, they tend to build up to a maximum.

In the form shown in Fig. 3, the source 8 is connected, as already described, to two vacuum-tube devices;'one of which 16 is like the tube 16 in Fig, 2. The grid biasing means in this figure has, however,

been shown as an adjustable C battery.

The second tube 25 is here shown as a mercury-arc device including a liquid mercury cathode 26 and two anodes 27 and 28. The anode 28 is connected to the positive side of the source 8 through a resistance 29 which is of such a size that current to the anode 28 will be just suflicient to maintain the arc. The secondary 11 is connected to an electromagnet 30 in a position to influence the arc. The direction of the windings in coils 11 and 19 and in the magnet 30 is such that, when current through the tube 16 is diminishing, the magnet will cause the arc to go to the anode 27, instead of the anode 28. This will cause an increase in the current through the tube 25, because the path through anode 27 avoids the resistance 29. Upon increase of current through the tube 16, the magnet 30 will cause the arc to return to anode 28. The resistance 29 then causes current through .the tube 25 to decrease, thus adding to the increase through tube 16. Accordingly, oscillations once'started will be sustained by the action. of. the tube connected in shunt to the tube 16.

In the form shown in Fig. 4,- similar connections are rovided, except that the tube 25, contains ut one anode 27. When the current through the tube 16'is maximum it shunts the tube 25 sufiiciently'to cause the arc to extinguish. The secondary 11, when the current throughv the tube 16 begins to dimlms'h applies a-pgtential to the grid of sep qee e Q s h hcauses the current of this tube'to increase and it increases to such a point that a spark passes between a terminal 32 within the tube 25 and the cathode 26. Thisspark sets up ionization and so starts the tube 25 to conducting again. Flow of current through the tube 25 shunts the tube 16 and thus causes further diminution in the current through this tube. Thus, oscillations once started in the circuit including condenser 7 and the inductor 19, the action of the shunted tube makes the oscillations build up.

It will be obvious that many variations of the specific construction employed can be used without departing from the spirit of this invention, I, therefore, do not propose to limit it except as necessitated by the prior art or indicated by the claims.-

I claim as my invention:

1. In an oscillation generator, a main circuit, a shunt, each including a space-current path, a common source supplying said main circuit and shunt with current, a grid in the space-current path of said shunt, means energized by current changes in said main circuit for varying the potential of said grid and thereby varying the impedance of said shunt, whereby the current changes in said main circuit are amplified, said amplification being eii'ected wholly by said variations in the impedance of said shunt.

2. In an oscillation generator, a main circuit, a shunt, each including a space-current path, a common source supplying said main circuit and shunt with approximately constant current, means associated with the space-current path of the shunt and energized by current changes in said main circuit for varying the impedance of said shunt, whereby the current changes in said main circuit are amplified, said amplification being efiected wholly by said variations in the impedance of said shunt.

3. In an oscillation generator, a main space-current device, a tuned circuit energized through said main space-current device, means associated with the shunt spacecurrent device, for altering the impedance thereof and means, energized from said tuned circuit, for controlling said impedance altering means, the impedence of said main space-current device being independent of the oscillations in said tuned circuit.

4. In an oscillation generator, a source of approximately constant direct current,,two parallel circuits supplied therefrom, a space current device in each of said circuits, means, including a grid, for controlling the impedance of one of said space-current devices and means for im ressing a varying potential on said grid whereby the current through but not theimpedance of the-o her vices, each having a grid, means for mainlast-named vacuum-tube device in accord taining one of said grids at a constant with the changes in the. impedance of the potential, means for impressing on the other vacuum.-tube device having a varying grid grid a potential varying in accord with the potential.

5 current changes through the vacuum-tube In-testimony whereof I aflixmy signature.

device having constant grid potential, and -mea for changing the current through the BRUNO ROSENBA ILM. 

